Class II malocclusions exist when an individual's upper jaw or maxilla protrudes further out from the individual's face than his/her lower jaw or mandible. Conversely, Class III malocclusions exist when an individual's lower jaw or mandible protrudes further out from the individual's face than his/her upper jaw or maxilla. Treatment of a Class II malocclusion may entail exerting a functional orthopedic force on the individual's lower jaw or mandible so as to advance the same in a mesial or “outward” direction.
One way in which orthodontic treatment forces have been applied to address a Class II malocclusion is through a facebow to retract the upper jaw or maxilla to match the position of a retruded mandible. As 70% of Class II malocclusions are due to a deficient mandible, it is more beneficial to the patient to advance the mandible than to retract the maxilla. This results in a better profile, and a more balanced facial appearance, compared to orthodontic techniques which retract the maxillary teeth to match the position of a retrusive mandible. The disadvantage of this approach is that the nose continues to grow, when the maxilla is retracted, and the nose becomes unduly prominent in the profile, while the maxilla and mandible are retracted to a retrusive position. This approach may align the anterior teeth, but at the same time, is detrimental to the patient's facial appearance. The alternative to a functional orthopedic approach to correct a mandibular retrusion would entail a combination of orthodontic and surgical correction to align the teeth and advance the mandible to match the correctly positioned maxilla. Orthopedic correction achieves a similar result by correcting the mandibular position without surgery in many cases. It is important to integrate orthopedic techniques with conventional orthodontic techniques, to allow the simultaneous correction of skeletal and dental abnormalities.
Another option which has been utilized to affect mesially-directed mandibular advancement is through what has been characterized in the orthodontic industry as “bite blocks.” Bite blocks generally include a planar surface which is disposed at an angle relative to an individual's occlusal plane when the bite blocks are installed on the patient. Typically a pair of bite blocks are installed on the occlusal surface of the patient's upper dental arch on opposite sides thereof (i.e., one on the right side of the upper dental arch, and another on the left side of the upper dental arch), while a pair of bite blocks are also installed on the occlusal surface of the patient's lower dental arch on opposite sides thereof (i.e., one on the right side of the lower dental arch, and another on the left side of the lower dental arch). Each of these bite blocks are installed so that there is a camming-like action between the two bite blocks which are occlusally installed on the patient's upper arch and their corresponding bite blocks which are occlusally installed on the patient's lower arch.
Both fixed and removable attachment techniques have been suggested for bite blocks generally of the above-noted type. “Fixed” in the orthodontic treatment sense and also as used herein means that a particular appliance is installed on the orthodontic patient in such a manner so that at least in theory the orthodontic patient will not be able to readily remove the appliance, but so that the appliance may be removed by the orthodontic practitioner utilizing the proper tool(s). “Removable” in the orthodontic treatment sense and also as used herein means that a particular appliance is installed on the orthodontic patient in such a manner so that the appliance may be readily removed by both the orthodontic patient and practitioner.
Since the beginning of the twentieth century, orthopedic appliances have traditionally been removable by the patient, therefore being dependent on patient cooperation to achieve the beneficial effects of treatment. The improvements of the present invention addressed below adapt the principles of orthopedic correction, already proven in removable appliance techniques, to fixed orthopedic appliances, thus allowing better control, and better results to be achieved by the unrestricted full time wear of orthopedic appliances.